09/18/2013

www.gupta-verlag.de/polyurethanes

'Terminator' poly(urea-urethane) elastomer that regenerates itself

The researchers, from the CIDETEC Centre for Electrochemical Technologies in San Sebastian, have dubbed the material a 'Terminator' polymer in tribute to the shape-shifting, molten T-1000 from the 'Terminator 2' film. The research is one of the first articles published in new Royal Society of Chemistry journal 'Materials Horizons'. Self-healing polymers that can spontaneously achieve quantitative healing in the absence of a catalyst have never been reported, until now. A video shows that the permanently crosslinked poly(urea-urethane) elastomeric network completely mends itself after being cut in two with a razor blade. The polymer behaves as a Velcro-like sealant or adhesive, displaying an impressive 97 % healing efficiency in just two hours. The researchers show that after cutting the material into two separate pieces with a razor blade and allowing it to self-heal, the material is unbreakable when stretched manually. The scientists prepared the self-healing thermoset elastomers from common polymeric starting materials using a simple and inexpensive approach. A metathesis reaction of aromatic disulphides, which naturally exchange at room temperature, causes the regeneration. The authors said: "The fact that poly(urea-urethane)s with similar chemical composition and mechanical properties are already used in a wide range of commercial products makes this system very attractive for a fast and easy implementation in real industrial applications.”

www.gupta-verlag.de/polyurethanes